This invention relates to a roll for rolling metals such as steel, aluminum and copper, a method of manufacturing the roll and a rolling mill incorporating the roll.
This invention is especially suitable for producing metal sheets having brightness, such as, for example, a stainless mirror plate in an oilstove or an aluminum foil.
Brightness is often required for a rolled sheet of steel, aluminum, copper, steel alloy, aluminum alloy or copper alloy. A rolled sheet having brightness is used as a mirror plate, a reflector plate and the like.
Previously, a roll produced by working an ingot of tool steel, high speed steel or the like has been employed for producing a rolled sheet. However, when, for example, rolling is conducted with such rolls a stainless steel, the roll can only stand a continuous use for a short time period of, for example, 10-15 minutes, and the length of sheet capable of being continuously rolled during such time period is about 1,000 m at the maximum. A longer use of the roll seriously deteriorates the brightness of the rolled sheet. Therefore, it is necessary to stop the run of the rolling mill to recondition the rolls when rolling has been conducted for 10-15 minutes in terms of rolling time and 1,000 m by the length of the rolled sheet. The time required for reconditioning the rolls is several times as long as the time of continuous rolling.
In, for example, Japanese Patent Publication No. 35874/79, a method of producing a Sendzimir roll by sintering steel powder has been proposed using high carbon and high vanadium steel powder produced by a water atomization process or a gas atomization process. However, it has not reported nor described in the Japanese Patent Publication that brightness of a rolled sheet could be heightened by using a sintered powder roll.